Response of improved common bean (Phaseolus vulgaris L.) varieties to intermittent drought

Resumen

Objective: To evaluate the response of 16 improved bean varieties to intermittent drought. Design/Methodology/Approach: A randomized complete block design was used, with four replications each under irrigated and drought conditions. The drought treatment consisted of suspending irrigation for 15 days in the flowering stage. The irrigation treatment consisted of maintaining available moisture above 60% throughout the cycle. The yield, its components, and days to physiological maturity were recorded. The drought tolerance of each variety was estimated using the drought susceptibility index, geometric mean, and productive mean.

Results: Drought reduced yield by 36%, the number of pods per plant by 28.5%, and days to physiological maturity by 0.7%. In contrast, the weight of 100 seeds increased by 4.9% and the number of seeds per pod was not affected. The Flor de Mayo Eugenia and Negro 8025 varieties were more tolerant to drought (p ≤ 0.05) than the rest of the varieties analyzed. These varieties recorded yields of 2,768 and 2,854 kg ha^-1 (irrigation) and 1,905 and 1,843 kg ha^-1 (drought), respectively.

Study Limitations/Implications: The drought intensity applied was relatively low, which could reduce the visibility of the differences between treatments.

Findings/conclusions: The secondary attribute with more sensitivity to intermittent drought was the number of pods per plant. The varieties with highest tolerance to droughts were Flor de Mayo Eugenia and Negro 8025.